/**
Save the volatile registers required to be restored following INIT IPI.
@param VolatileRegisters Returns buffer saved the volatile resisters
**/
VOID
SaveVolatileRegisters (
OUT CPU_VOLATILE_REGISTERS *VolatileRegisters
)
{
UINT32 RegEdx;
VolatileRegisters->Cr0 = AsmReadCr0 ();
VolatileRegisters->Cr3 = AsmReadCr3 ();
VolatileRegisters->Cr4 = AsmReadCr4 ();
AsmCpuid (CPUID_VERSION_INFO, NULL, NULL, NULL, &RegEdx);
if ((RegEdx & BIT2) != 0) {
//
// If processor supports Debugging Extensions feature
// by CPUID.[EAX=01H]:EDX.BIT2
//
VolatileRegisters->Dr0 = AsmReadDr0 ();
VolatileRegisters->Dr1 = AsmReadDr1 ();
VolatileRegisters->Dr2 = AsmReadDr2 ();
VolatileRegisters->Dr3 = AsmReadDr3 ();
VolatileRegisters->Dr6 = AsmReadDr6 ();
VolatileRegisters->Dr7 = AsmReadDr7 ();
}
}
/**
Trigger one software interrupt to debug agent to handle it.
@param Signature Software interrupt signature.
**/
VOID
TriggerSoftInterrupt (
UINT32 Signature
)
{
UINTN Dr0;
UINTN Dr1;
//
// Save Debug Register State
//
Dr0 = AsmReadDr0 ();
Dr1 = AsmReadDr1 ();
//
// DR0 = Signature
//
AsmWriteDr0 (SOFT_INTERRUPT_SIGNATURE);
AsmWriteDr1 (Signature);
//
// Do INT3 to communicate with HOST side
//
CpuBreakpoint ();
//
// Restore Debug Register State only when Host didn't change it inside exception handler.
// Dr registers can only be changed by setting the HW breakpoint.
//
AsmWriteDr0 (Dr0);
AsmWriteDr1 (Dr1);
}
/**
Store debug register when SMI exit.
**/
VOID
SaveDebugRegister (
VOID
)
{
mSavedDebugRegisters[0] = AsmReadDr0 ();
mSavedDebugRegisters[1] = AsmReadDr1 ();
mSavedDebugRegisters[2] = AsmReadDr2 ();
mSavedDebugRegisters[3] = AsmReadDr3 ();
mSavedDebugRegisters[4] = AsmReadDr6 ();
mSavedDebugRegisters[5] = AsmReadDr7 ();
}